Warbler said:

I felt was ok to have two-face in the movie, and his creation was handled very well. But why did they have to kill him off? They should have left the two-arc at the point where Dent was in the hospital bed mentally turning into Two-Face. Two-Face could have been the main villain in the 3rd movie. Other than that, I think the Dark Knight was great. I think there should only be 1 villain per movie.

Like I said, I'm rather glad they killed him off. I think his descent into villainy was far more interesting than a Two-Face crime spree would have been. So it just would have been a let down. Besides the fact that his objectives had mostly been accomplished at this point. He was mourning Rachel (oh, and the fact that Harvey actually validated the existence of the character of Rachel Dawes also earned so many points in my book as well) and getting his revenge by giving those responsible a 50/50 chance as well. What else was there for him to do? I think if he had taken the next movie solo, he would have overstayed his welcome, so I just love the way they did it in The Dark Knight.